A typical walkie/rider pallet truck includes load carrying forks and a power unit having a steerable wheel, a steering control unit, a brake, an electric traction motor, a storage battery, a platform onto which the operator may step and ride while controlling the truck and a pivotable restraint structure. The steering unit normally has a handle mounted at the end of a movable steering arm with the handle including controls for raising and lowering the forks and one or more rotatable devices to control the speed and direction (forward and reverse) of the truck.
In stock picking operations, a truck operator typically follows a winding, unidirectional route through a warehouse, picking up stock in a predetermined sequence in order to maximize productivity. The operator normally walks alongside the truck when the distance along the route between picks is short and steps onto the truck platform to ride when the distance between picks is longer. When the operator is riding on the truck platform, it is desirable for optimum work productivity to move the truck at higher speeds than when the operator is walking beside it.
In dock applications, a truck operator typically drives in and out of trailers, or drives in certain storage lanes in a shipping or receiving area of a warehouse. The operator often gets on and off the truck to scan barcode labels on a pallet, which is located on the forks. Or, in some cases, the operator may need to adjust the pallet for better stacking or storing in the trailer.
Prior art pivotable U-shaped restraint structures are typically positionable in either a stowed position or a rider-driving position. The restraint structures include side elements that extend along opposing sides of an operator when the operator is standing on the platform and the restraint structure is in the rider-driving position. The side elements are integral with an intermediate element that extends between the side elements so as to define the U-shaped restraint structure. When in a stowed position, the restraint structure may be positioned in either a substantially downward, vertical or near vertical position adjacent to the truck power unit or positioned in a horizontal or near horizontal position over the truck power unit. Hence, to move the restraint structure from its stowed position to its rider-driving position, an operator must bend over and lift the restraint structure from its downward stowed position or reach out over the power unit main housing and lift up the restraint structure from its stowed position out over the power unit main housing. The lifting operation is disadvantageous.
Other prior art restraint structures comprise a pair of inwardly foldable restraint members, wherein each restraint member is separately coupled to the truck power unit. Typically, the restraint members are positionable in a first stowed position against the power unit and a second, outwardly extending position so as to extend along opposing sides of an operator when the operator is standing on the platform. When exiting a side of the platform, an operator typically steps backwards off the end of the platform without folding-up the restraint members, then steps sideward around the restraint, and then walks forward to the fork area. This operation requires extra walking steps which is time consuming and, hence, inefficient. Alternatively, the operator could also step off the side of the platform. In this case, the operator must move his body toward the opposite side of the platform in which he wants to exit, then pivot the opposing restraint member inward against the power unit, and then step off the open side of the truck. This operation requires fewer walking steps, but also requires extra movement of the body, which is time consuming and, hence, inefficient.